Process for producing silicon carbide single crystals

Abstract

The process for producing silicon carbide single crystals of the present invention comprises a step for growing single crystals of silicon carbide on a silicon carbide seed crystal by supplying a sublimed gas of a silicon carbide source material to the silicon carbide seed crystal arranged on a pedestal, wherein a spacing member composed of silicon carbide is arranged between the pedestal and the silicon carbide seed crystal, the spacing member is non-adhesively held on the pedestal by a supporting member, the silicon carbide seed crystal is adhered to the surface of the spacing member on the opposite side of the pedestal, and the spacing member and the supporting member are relatively arranged so that the adhesive surface of the spacing member adhered with the silicon carbide seed crystal is separated by 5 mm or more in the vertical direction from the lowest position of the supporting member.

1 . A process for producing silicon carbide single crystals, comprising: a step for growing single crystals of silicon carbide on a silicon carbide seed crystal by supplying a sublimed gas of a silicon carbide source material to the silicon carbide seed crystal arranged on a pedestal; wherein,
 a spacing member composed of silicon carbide is arranged between the pedestal and the silicon carbide seed crystal,   the spacing member is non-adhesively held on the pedestal by a supporting member,   the silicon carbide seed crystal is adhered to the surface of the spacing member on the opposite side of the pedestal, and   the spacing member and the supporting member are relatively arranged so that the adhesive surface of the spacing member adhered with the silicon carbide seed crystal is separated by 5 mm or more in the vertical direction from the lowest position of the supporting member.   
     
     
         2 . The process for producing silicon carbide single crystals according to  claim 1 , wherein the adhesive surface of the spacing member is subjected to curvature processing to match the warped shape of the silicon carbide seed crystal. 
     
     
         3 . The process for producing silicon carbide single crystals according to  claim 1 , wherein the difference in the amount of warp between the spacing member and the silicon carbide seed crystal is ±5 μm or less. 
     
     
         4 . The process for producing silicon carbide single crystals according to  claim 1 , wherein the spacing member is formed with any of polycrystals, single crystals or sintered compact. 
     
     
         5 . The process for producing silicon carbide single crystals according to  claim 1 , wherein the spacing member is composed of a plurality of layers. 
     
     
         6 . The process for producing silicon carbide single crystals according to  claim 5 , wherein buffering layers are provided between the plurality of layers. 
     
     
         7 . The process for producing silicon carbide single crystals according to  claim 1 , wherein
 the spacing member is provided with a support holder around the outer periphery thereof,   the supporting member is provided with a hook on the lower portion thereof, and   the support holder of the spacing member is supported by the hook of the supporting member.   
     
     
         8 . The process for producing silicon carbide single crystals according to  claim 1 , wherein
 internal threads are formed in the inner periphery of the supporting member,   external threads that engage with the internal threads are formed on the outer periphery of the pedestal, and   spacing between the pedestal and the spacing member can be adjusted by relatively rotating the supporting member and/or the pedestal.   
     
     
         9 . The process for producing silicon carbide single crystals according to  claim 1 , wherein the supporting member is composed of graphite. 
     
     
         10 . The process for producing silicon carbide single crystals according to  claim 1 , wherein a buffering member is provided between the pedestal and the spacing member. 
     
     
         11 . The process for producing silicon carbide single crystals according to  claim 10 , wherein the buffering member is composed of grafoil, carbon felt or a high melting point metal.